1. Field of the Invention
The present invention relates to a keypad assembly for electronic equipment, and more particularly, to a keypad assembly for electronic equipment, in which an optical filter layer is formed at a key button so as to selective emit light in response to the wavelength of light irradiated to the optical filter layer.
2. Description of the Related Art
Portable communication devices include portable devices that can be used for wireless communications. Such a portable communication device includes a keypad as a data input unit. A user can input data to the portable communication device by pressing a button of the keypad using a finger.
FIG. 1 is a cross-sectional view illustrating a conventional keypad assembly 10.
Referring to FIG. 1, the conventional keypad assembly 10 includes a light emitting unit 20, a light guide plate 30 guiding light emitted from the light emitting unit 20, a plurality of key buttons 40 formed on a top surface of the light guide plate 30 and including printed numeral and character key surfaces, a plurality of protrusions 50 protruded from a bottom surface of the light guide plate 30 in correspondence with the key buttons 40, a plurality of reflection patterns 31 formed on the bottom surface of the light guide plate 30 in correspondence with the key buttons 40 so as to direct the light guided by the light guide plate 30 toward the key buttons 40, and a switch substrate 60 disposed under the protrusions 50 and including a plurality of dome switches 61 corresponding to the protrusions 50.
Light (B) emitted from the light emitting unit 20 is guided by the light guide plate 30 and reflected by the reflection patterns 31. Thus, the light (B) can be directed to the key buttons 40 so as to illuminate the numeral and character key surfaces of the key buttons 40.
In this case, although the entire key buttons 40 can be illuminated using the single light emitting unit 20 and the light guide plate 30, the numeral and character key surfaces of the key buttons 40 cannot be separately illuminated.